Overview
Mieszko the Younger (also known as of Kalisz) (between 1160 and 1165 – 2 August 1193) was a Duke of Kalisz from 1191 until his death.
He was the second child (but fourth-born son) of Mieszko III the Old, Duke of Greater Poland and from 1173 High Duke of Poland, due to his marriage to his second wife Eudoxia, daughter of Grand Prince Iziaslav II of Kiev.
Life
We do not know when he was born. His older brother, Bolesław, was born in 1159, while his younger brother Władysław Laskonogi was alive in 1166 or 1167.
Mieszko is documented earliest in 1166 or 1167, in a document signed between Mieszko III and Casimir II the Just at the congress in Jędrzejów, as one of the sons of the Duke of Greater Poland.
From Wikipedia (CC BY-SA 4.0).